To tell the truth, I have no idea. Development is of Mangle, Arabica's XSLT engine, is ongoing, although progress varies according to the vagarities of how busy I am, how energetic I'm feeling, whether the kids have a swimming gala, and so on and so forth.

Although it's not done yet, it might well be done enough. I'm using the OASIS XSLT test suite to help drive development, and so it also provides a measure of how much has been done, what's working and what isn't. The results are published here, but all the code and test data is included in the download. The executive summary is the core stuff that you use every day works, but some of the bits round the edges (edges defined by my experience, anyway) are missing.

To my knowledge there's nothing that causes Mangle to crash, and anything that I haven't yet implemented generates a warning when the stylesheet is compiled.